Air-lock system for continuously operated vertical cement kilns



F. P. SOMOGYI Sept. 16, 1952 AIR-LOCK SYSTEM FOR CONTINUOUSLY OPERATED VERTICAL CEMENT KILNS Filed April 26, 1950 Inventor Francis Paul Somoggi,

i5 Attorney Patented Sept. 16, 1952 AIR-LOCK SYSTEM FOR CONTINUOUSLY OPERATED VERTICAL CEMENT KILNS Francis Paul Somogyi, London, England Application April 26, 1950, Serial No. 158,106

4 In Great Britain November 18, 1949 Claims. 1

a continuously operated vertical cement kiln.

In the production of cement, raw material is heated in a kiln of the type referred to above, the material being charged, together with a solid fuel, into the kiln through the top thereof and subsequently discharged therefrom, after heating, through a chute the receiving end of which is in communication with the bottom of the kiln. Air for the combustion of the solid fuelis supplied to the kiln at the bottom thereof, at a pressure above that of the surrounding atmosphere.

Since successful and efficient operation of the kiln depends to a large extent on a steady supply of air, egress of air through the chute is therefore undesirable and detrimental and should be reduced to a minimum.

In this connection it has been proposed to form an air-lock between the kiln and the discharge end of the chute by pivotally mounting within the chute at least two flap-gates, each flap-gate being opened and closed in succession so that at least one of the flap-gates is always closed. The flap-gates are kept in their closed position by the action of a restoring force, e. g. a balance weight, and they are positively opened by periodically operated actuatin means consisting of a cam and lever mechanism which overcomes the closing action of the restoring force.

In practice, however, it can happen that the pressure of the air in the kiln rises above the critical value and overcomes the restoring force of the balance weight, with the result that the flap-gates are blown open allowing air to escape. The above described construction also does not allow of operating the kiln at .higher pressures, as e a rather heavy balance weight would be required which is inconvenient and undesirable.

Moreover, there is the danger that some bigger particles may come to rest between the flap-gate and the frame of the chute against which the flap-gate bears so that a tight closure is prevented.

According to the present invention the above difficulties are overcome by means of an air-lock system for a continuously operated vertical cement kiln having a chute with an inclined floor down which material discharged from the kiln flows, the said system comprising a flap-gate which is mounted in the chute and arranged to be opened positively against the action ofa restoring force, by periodically operated actuating means, and which is provided with periodically operated locking means adapted to tighten the closure and also to keep the flap-gate in its closed position 2 between the periodswhen it is caused to open by the periodically operated actuating means.

In a preferred construction the flap-gate is locked in the closed position by a lock operating lever arranged periodically to engage a locking lever mounted on the flap-gate spindle. Preferably the fiap-gate is connected pivotally to the wall of the chute by means of a spindle to which are connected (a) a closing lever, actuated by a restoring force (e. g. a balance weight) causing the closure of the flap gate (2)) an operating lever of a leverand cam mechanism imparting to the flap-gate the opening movement and (c) a locking lever which is adapted to co-act with the free end of a lock operating lever which is urged into its locking position by a restoring force (a. g. a balance weight) and caused to move into the release position by a lever mechanism actuated by means of a cam.

It as advantageous to provide the free end of the lock operating lever with a cam follower and to give the locking lever the form of a cam-way, one part of which cam-way forms the locking face whilst the remaining part forms a riding surface for the lock operating lever during the opening and closing movement of the flap-gate. The lock operating lever is free to rotate around a pivot and the locking face of the cam way has an initial part concentric with the axis of said pivot whilst the distance of the following part from pressure within the kiln, and the kiln can now be. operated at a higher. pressure, which gives the best possible operating conditions and at the same time improves the efficiency of the kiln. The new arrangement also ensures a positive closure of the flap-gate during the last part of its closing movement.

Preferably the air-lock system is of the kind described and claimed in my co-pending application Serial No. 158,105, filed April 26,1950 in which a segmental gate is pivotally mounted in the chute before each flap-gate, each segmental gate being arranged to swing out of a well in the inclined floor to arrest the flow, of material before the. succeeding flap-gate closes and subsequently to swing back into the well, when'the succeeding flap-gate is again open, to allow the flow of material to be resumed.

A preferred embodiment of the invention will now be described by way of example with reference to the accompanying drawing, the single figure of which shows diagrammatically, in side elevation, the lower part of a discharge chute.

Referring now to the drawing a vertical cement kiln (not shown) has a chute I (the lower part only of which is shown for clarity) disposed at the bottom thereof. The chute has an inclined floor 2 down which material discharged from the kiln flows, the receiving end of the chute being in communication with the bottom of the kiln.

A segmental gate 3 is pivotally mounted in the chute near the lower end thereof and arranged. to swing out of a well 4 in the floor 2 to arrest.

mounted on a closing lever ll attached to the pivoted shaft or spindle of the gate 3 and lying in back of the chute: A flap-gate 5 is pivotally mounted in the chute-below the segmental gate in the directionof' flow; and arranged to close against a seat 6 to prevent egress of air through the chute. The gates" 3 and 5 are positively opened against a restoring force by means of linkages I and 1a '(shown' only schematically), actuated from cams 8 and 8' mounted on a shaft 8a. The restoring force for the gate 5 is provided' by a balance weight I mounted on a closing lever l2 attached to the outside of the spindle of the gate'5, the weight being so dimensioned and positioned'as to'cause the closing of the gate up to a position'where the locking device exerts its locking pressure. Also attached to the spindles of'the gates 5 and 3 in back of the-chute, as indicated by dotted lines, are arms'l' and II respectively to which the linkages-1 and la are pivotally attached in a known manner, which linkages are similar'to the lock opening and releasing means including'lever and linkage 2!, more fully described hereinafter.

The closing lever 12 for the gate'5 is extended beyond its pivot on spindle 5, and this extension has the shape of a quadrant, which forms the locking lever [3 adapted to co-operate with a lock-operating lever IS. The quadrant has a cutout l4 where the lower edge of the leverand the periphery of the quadrant [3 meet, thus forming together with the periphery ofthe quadrant a cam way. A bell crank lever is mounted on a pivot [5 on the outside of'the chute and has one arm which constitutes the lock. operating lever [6, the other arm having a balance weight I! mounted thereon and so positioned that it urges the lock operating lever l 6 into engagement with the cut-out I4 after the flap-gate 5 has been closed. The engaging end of the lock operating lever I6 has a roller [8 mounted thereon to provide for a rolling engagement-between the locking lever and the cam way of thequadrant. The lock operating lever is actuated from a cam 19 mounted on the shaft 8a through a lever 20 and a linkage 2| connected to the engaging end of the lock operating lever l6.'

The initial part of the cut-out I4 starting from the circular edge of the quadrant I3, is concentric with the pivot l5, whilst the following part gradually decreases to produce a wedge action'in order to enforce a tight closure of'the flap-gate 5. An additional segmental gate and flap-gate (not shown) which generally correspond to the arrangement disclosed in my before mentioned copending application are similarly disposed in the chute 1 near the upper end '(not shown) thereof, in like relationship and actuated in like manner to the said additional flap-gates 3 and 5 described above. the gates being provided with a locking means in like manner to the locking lever I 3 and lock operating lever 16. The cams (not shown) for actuating the upper gates and the upper locking means are mounted on the shaft 8a and are out of phase with the cams 8,'8" and I9 respectively so that the upper gates are always closed when the lower gates 3 and 5 are open and vice versa.

The upper flap-gate, the upper segmental gate and the gates 3 and 5 each remain closed for more than half of a complete cycle, i. e. for more than half a complete revolution of the cam shaft 8a. -At the commencement of the second half cyclev the upper gates are already closed and locked and the flap-gate 5 then commences to open and is again closed a little before the end of the second half cycle.

The cam, actuating the:1ock'operati1ig.lever'|6, is so designed andpositioned/that tl'xisslever is Withdrawn from the wlocking-fame ofthe iquadrant IS a little before the nap-gate 5 commences to open at the beginning of.the'seconduhalfecycle. During the opening and closing'movement ofthe gate 5 the rollerJB on the locking-lever 16 rides on the periphery of". the quadrant"l3 and-after the flap-gate is .fully; closed the locking lever is again urged into. engagement 'with the: notch I 4 by the restoringaction ofthevbalance weight H. The locking means 'assoclatedwith. the upper gates (not' shown) operate in likeuman-ner'and therefore need .no further description:

The materialpdischarged fromzthechutel is fed onto a suitable conveyor 22.

Having now particularly-described and ascertained the nature of ms said inventiom-"and in what manner-the same isto'abe performed, I declare that what I claim-'isz 1. An air-lock system fora continuouslygoperated vertical cementxkiln having :a chute with an inclined floordown which material discharged from the kiln'fiowspthe. said-chutev comprising a flap-gate pivotally mounted-in the chute',:restoring means adapted to hold: the.flap-gate in its closed position, periodically operated actuating means for opening the: fiapngate against the action of the restoring means, locking means adapted to tightenrthe closure and also..tokeep the flap-gate in. its closed position between .the periods when it is caused touopenby the periodically operated actuating means and lock-releasing means operable intimed-relationship. with said actuating means.

2. An ,air-locksystem' for a continuously operated verticalzcement kiln 'havinga-a chute with an inclined floor. down which material discharged from the kiln .fiows, the said-chute comprising a flap-gate, a shaft mounted-in: the'chute free to rotate and connected to'theflap-gateprestoring means adapted: to hold the; flapvgate in its closed position, periodically operated actuating means for opening the fiap-gatesagainsr the action of the restoring means -periodically operatedlocking means adapted to tightenthe closure and also to keepqthe fiapegatein' itsrclosed position between the periods-when it is caused-to open by the --periodically operated: actuating means, said locking means comprising a locking lever connected to said flap-:gate' shaft; and a lock-operating lever-adapted-to eo-act with the said locking lever.-

3. .An air-lock system: for-a continuously operated vertical cement kiln having a chute with an inclined floor down which material discharged closure of the flap-gate and connected to the shaft of the flap-gate, a cam and lever mechanism including an operating lever for imparting the opening movement to the flap-gate connected to the shaft of the flap-gate, a locking lever connected to the shaft of the flap-gate, a lock-oper ating lever, co-acting with said locking lever and having a locking position and a release position,

another restoring means urging said lock operating lever into its locking position, and a cam and .lever mechanism causing the lock-operating lever to move into the release position.

i. Anair-lock system for a continuously operated vertical cement kiln having a chute with an inclined floor down which material discharged from the kiln flows, the said chute comprising a flap-gate, a shaft mounted in the chute free to rotate and connected to the flap-gate, a restoring means adapted to hold the flap-gate in its closed position, periodically operated actuating means for opening the flap-gate against the action of the restoring means, periodically operated locking means adapted to tighten the closure and also to keep the flap-gate in its closed position between the periods when it is caused to open by the periodically operated actuating means, said locking means comprising a locking lever connected to said flap-gate shaft, and a lock-operating lever adapted to co-act with the said locking lever, a cam follower at the free end of said lock-operating lever, and a cam-way formed by said locking lever, one part of the cam-way forming a locking face and the remaining part forming a riding surface for the lock-operating lever during the opening and closing movement of the flap-gate.

5. An airlock system for a continuously operated vertical cement kiln having a chute with an inclined floor down which material discharged from the kiln flows, the said chute comprising a flap-gate, a shaft mounted in the chute free to rotate and connected to the flap-gate, a restoring means adapted to hold the flap-gate in its closed position, periodically operated actuating means.

for opening the flap-gate against the action of the restoring means, periodically operated looking means adapted to tighten the closure and also to keep the flap-gate in its closed position between the periods when it is caused to open by the periodically operated actuating means, said locking means comprising a locking lever connected to said flap-gate shaft, and a lock-operating lever adapted to co-act with the said locking lever, a cam follower at the free end of said lock-operating lever, a cam-way formed by said lockin lever, one part of the cam-way forming a locking face and the remaining part forming a riding surface for the lock-operating lever during the opening and closing movement of the flapgate, said lock-operating lever being free to swing around a pivot, and said locking face of said camway being so shaped that its initial part is concentric with the axis of the said pivot, whilst the distance of the following part from the pivot gradually decreases to produce a wedge action.

6. An air-lock system for a continuously operated vertical cement kiln having a chute with an inclined floor down which material discharged from the kiln flows, the said chute comprising a flap-gate, a shaft mounted in the chute free to rotate and connected to the flap-gate, a restoring means adapted to hold the flap-gate in its closed and the remaining part forming ariding, surface for'the lock-operating lever during the opening and closing movement of the flap-gate, said locking -lever has the shape of a quadrant, the lower edge of whichfor'ms said locking face of the cam and the periphery of which serves as riding surface for the follower of the lockeopera-ting lever during the opening and closing motion of the flap-gate I 7. An air-lock system fora continuously operated vertical cement kiln having a chute, with an inclinedfloor' down which material discharged from the kiln flows, the said chute comprising a flap-gate, a shaft mounted in the chute free to rotate and connected to the flap-gate, a closing lever actuated by a restoring means causing the closure of the flap-gate and connected to the shaft of the flap-gate, a cam and lever mechanism including an operating lever for imparting the opening movement to the flap-gate connected to the shaft of the flap-gate, a locking lever connected to the shaft of the flap-gate, a lock operating lever, co-acting with said locking lever and having a locking position and a release position, another restoring means urging said lock operating lever into its locking position, and a cam and lever mechanism causing the lock-operating lever to move into the release position, said lockoperating lever being formed as a bell-crank lever, one end of which being arranged to co-act with said locking lever and the other end being provided with a balance weight urging the bellcrank lever into its locking position.

8. An air-lock system for a continuously operated vertical cement kiln having a chute with an inclined floor down which material discharged from the kiln flows, the said chute comprising a flap-gate, a shaft mounted in the chute free to rotate and connected to the flap-gate, a restoring means adapted to hold the flap-gate in its closed position, periodically operated actuating means for opening the flap-gate against the action of the restoring means, periodically operated looking means adapted to tighten the closure and also to keep the flap-gate in its closed position between the period when it is caused to open by the periodically operated actuating means, said locking means comprising a locking lever conneoted to said flap-gate shaft, and a lock-operating lever adapted to co-act with the said locking lever and provided with a cam follower, said locking lever having the shape of a cam-way, one part of the cam-way forming a locking face and the remaining part forming a riding surface for the lock operating lever during the opening and closing movement of the flap-gate, said periodically operated locking means being so designed that it only causes the locking end of said lockoperating lever to move out of the range of the locking face in order to release the flap-gate, whilst the remaining movement of the lock-operating lever is determined by the movement of its 7. follower along said riding surfa'ce'ofsaidlooking lever.

9. An air-lock system forra continuouslyoperated vertical cement kiln having a chute withan inclined floor down' which material discharged from thekiln flows, thesaid chute comprising a flap-gate, a shaftmounted in the chute free to rotate and connected to the flap-gateya restoring means adapted to hold the flap-gate'in itsclosed position, periodically operated: actuating, means for opening the flap-gate against the'acti'on oi'the restoring means, periodically operated locking means adapted totighten the closure and alsoto keep the flap-gate in its closed position between the periods when it is. caused-to open "bythe periodically operated actuating means, saidlooking means comprisin a .iocki'ng' lever connected to said flap-gate shaft, and a lock-operating lever adapted to co-act with the'said locking lever, said locking lever having the shape'ora cam-wamone part of the cam-way forming a locking fa'oeand the remaining part forming a riding surface for the lock-operating lever during the opening and closing movement of theflap-gate; said periodically operated locking means comprising a driving cam and a lever system activated by said'cam, said driving cam being so shaped that it causes the lock operating lever to releasethe'flap-gate a short time before the opening movementis 1mparted to the flap-gate.

10'. An air-lock-system-ior a continuously operated vertical cement kiln having a. chute-with an inclined floor down which material discharged from the kiln flows, the saidchute comprising a flap-gate pivotally mounted in the chute, a restoring means adapted to hold the flap-gate in its closed position, periodically operated actuating means for opening the flap-gate against the-action of the restoring means, periodically'operated locking means adapted to tighten the closure and alsoto keepthe flap-gate in its closed position between the periods when it is caused to openby the periodically operated actuatingmeans, a driving cam imparting -motion to said periodically operated actuating-means and-a driving cam imparting motion to said periodically operated looking means, both said driving cams being arranged on the'same shaft."

FRANCIS PAUL 'SOMOGYI.

REFERENCES CITED FOREIGN PATENTS Country Date France July 15, 1924 Number 

